How to adjust the exposure parameters in portrait photography, and what are the setting skills?

The exposure of portrait photography, like the exposure of other subject photography, is ever-changing and complicated, but it can be used freely after mastering certain rules.

1, the alternation of seasons, spring, summer, autumn and winter, and the angle at which the sun shines on the earth's surface is also changing. Among the four seasons, summer is the strongest, winter is the weakest, and spring and autumn are between Xia Dong. The light in winter is low, which is only equivalent to 1/4 in summer, and the light in spring and autumn is moderate, which is equivalent to 1/2 in summer. So under the same shooting conditions, such as shooting at noon in summer,

1125 seconds, F 1 1125 seconds in winter and F 16,1/kloc in spring and autumn.

2. Changes in geographical conditions Changes in geographical conditions are divided into changes in latitude and altitude of the earth. Due to the different angles between the sun and the earth, different illumination angles are formed. The closer to the equator, the lower the latitude, and the sun shines almost vertically, with the strongest illumination. The farther away from the equator, the higher the latitude, the greater the oblique angle of the sun, and the weaker the illuminance. About every latitude difference of 15, the illumination difference is about 1 times, and the aperture increases or decreases by 1 level during exposure.

Altitude also affects the change of exposure. The higher the terrain, the less moisture and dust, and the stronger the light, so reduce the exposure when shooting at the plateau. Generally speaking, from the sea level, the exposure decreases 1000m, and at 2000m, the exposure decreases 1/4 and 1/3.

The exposure at 3000m decreases 1/2, and the exposure at 4000m decreases by 3/4.

The change of weather directly affects the intensity of light. The changes of sunny and cloudy weather can be roughly divided into four categories: clear Wan Li, thin clouds covering the sun, dark clouds covering the sun and overcast clouds. The exposure of these four weather types can be said to be about 1 times in turn. For example, under the same shooting conditions, if the aperture is unchanged, it takes1125 seconds to shoot in sunny days, 1/60 seconds for thin clouds to cover the sun, 1/30 seconds for dark clouds to cover the sun, and1/kloc-for dark clouds to cover the sun.

4. Changes in light The exposure rules in the above three aspects are all described by taking light as an example, and changes in the angle of light will also cause different changes in exposure. Taking the portrait under the forward light as an example, it is assumed that under the same conditions, the side light is 1-2 levels larger than the portrait under the forward light, while the backlight is 2-3 levels larger. Such as f 16 for front light, f 1 1 or f8 for side light, f8 or f5.6 for backlight.